Prevention of venous thrombosis after coronary artery bypass surgery (a randomized trial comparing two mechanical prophylaxis strategies)

Although venous thrombosis may occur often after coronary artery bypass grafting, prophylaxis with low-dose heparin is rarely used due to the risk of bleeding. Therefore, we compared the efficacy of 2 mechanical regimens of prophylaxis against deep vein thrombosis (DVT). Consecutive patients undergoing coronary artery bypass without concomitant valve surgery or coronary endarterectomy were randomized to either a more intensive regimen of intermittent pneumatic compression (IPC) plus graduated compression stockings (GCS) versus standard compression stockings alone. Of 611 patients screened, 184 were excluded due to peripheral vascular disease, postoperative intraaortic balloon support, or immediate postoperative anticoagulation. An additional 83 patients refused consent, leaving 172 in each prophylaxis group. The primary study end point was DVT diagnosed by a predischarge leg ultrasound examination performed on postoperative days 4 to 6. Of 344 patients enrolled, 330 (96%) underwent pre-discharge ultrasonography. DVT was detected in 19% of patients assigned to IPC plus stockings versus 22% assigned to GCS alone (95% confidence interval for the difference, −11% to 6%, p = 0.62). The addition of IPC did not add significant incremental benefit to GCS alone for DVT prophylaxis among patients undergoing coronary artery bypass surgery.